#include <bits/stdc++.h>
using namespace std;
const int N = 100'000 + 10,
M = 1'000'000'007;
int n;
int d[N], x[N];
void add(int& x, const int& y) {
x += y;
if (x >= M) x -= M;
};
namespace sub2 {
int f[N];
void solve() {
for (int i = 1; i <= n; ++i) {
auto& ret = f[i];
if (i == 1) ret = 1;
if (!d[i]) continue;
for (int j = 1; j <= x[i]; ++j) {
int t = i + j * d[i];
if (t > n) break;
add(f[t], ret);
}
}
int answer = 0;
for (int i = 1; i <= n; ++i) add(answer, f[i]);
cout << answer << "\n";
}
}
namespace sub3 {
int bit[N];
void upd(int i, int x) {
for (; i <= n; i += i & -i) add(bit[i], x);
}
int que(int i) {
int ret = 0;
for (; i; i -= i & -i) add(ret, bit[i]);
return ret;
}
void solve() {
upd(1, 1); upd(2, -1);
for (int i = 1; i <= n; ++i) {
int ret = que(i);
upd(i + 1, ret);
upd(i + x[i] * d[i] + 1, M - ret);
}
int answer = 0;
for (int i = 1; i <= n; ++i) add(answer, que(i));
cout << answer << "\n";
}
}
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for (int i = 1; i <= n; ++i) cin >> d[i] >> x[i];
if (n <= 10'000) { sub2::solve(); return 0; }
if (all_of(d + 1, d + n + 1, [](const auto& a) { return a == 1; })) {
sub3::solve();
return 0;
}
}
